| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic laser power control circuit which can be applied, regardless of the grounding type of a monitor diode which monitors the power of a laser diode. SOLUTION: Laser beams are projected, in response to the voltage applied, and the electric signal of a voltage in proportion to the power of the projected laser beams is outputted. A voltage adjusting part adjusts a voltage to be applied to a laser diode package 31, based on the voltage of the electric signal outputted from the laser diode package 31. Then, a polarity adjusting part changes the polarity of the voltage of the electric signal outputted from the laser diode package 31 to the polarity of the voltage applied to the laser diode package for supplying the voltage to the voltage adjusting part. Thus, a monitor diode can be compatibly used, regardless of its grounding type. |
